Bilateral pleural effusion revealing a rare breast tumor: A case report

Malignant pleural effusions are common in patients with neoplastic disease [1]. They also account for 42-77% of exudative effusions [1]. And among all the malignancies associated with this entity, breast cancer is the main cause in more than half of the cases in women.

Lobular breast carcinomas cannot be ruled out, as they represent the second most common histological form of breast carcinoma (5–15%) after infiltrating duct carcinoma [2]. The patterns of spread of metastatic lobular and ductal carcinoma of the breast are different. Lobular carcinoma commonly metastasizes to the peritoneum, gastrointestinal tract, bones, and ovaries with a lower incidence of extension to the lungs or pleura [3]. Pleural effusions in these malignancies usually occur at an advanced stage of the disease. However, they can be the revealing manifestation, as our case study proves.

Treatment decisions should be based on the individual patient and the biological characteristics of the tumor. However, it has been reported that lobular carcinoma responds less well to chemotherapy [4].

We report the case of a 61-year-old woman with a history of well-controlled asthma, diagnosed at age 20 and treated with inhaled corticosteroids in combination with long-acting beta2-agonists, who was consulted for Stage III by Modified Medical Research Council Score (mMRC) Dyspnea accompanied by wheezing and pleuritic chest pain for two months. Physical examination revealed a weight loss of 13 kg in two months.

At presentation, her blood pressure was 120/70 mm Hg, pulse was 95/min and regular, respiratory rate was 25 breaths/min, and oxygen saturation, measured by pulse oximetry, was 90% in room air. Respiratory examination showed decreased breath sounds in the bilateral mid-lung fields with dullness on percussion.

Chest examination revealed a 1 cm mobile lump in the upper outer quadrant of the left breast with no palpable axillary lumps. There was nipple retraction; the mobile knot had a hardened consistency and did not adhere to deep structures.

She had no lymphadenopathy. The rest of the examination was normal. Chest X-ray showed a moderate bilateral pleural effusion (Fig 1). The chest CT scan also confirmed the bilateral pleural effusion.

Chest X-ray shows moderate bilateral pleural effusion (yellow arrows).

Analysis of right pleural fluid obtained by thoracentesis showed exudate with elevated fluid protein, while serum protein, fluid lactate dehydrogenase, and serum lactate dehydrogenase were within normal ranges (Table 1). No acid-fast bacilli were detected in the pleural fluid and cytology was negative for malignant cells. A percutaneous biopsy of the right pleura was performed and the diagnosis was pleural metastases from breast carcinoma.

laboratory test value reference range
Liquid protein (g/L) 45 <20
Serum protein (g/L) 70 60-80
Liquid lactate dehydrogenase (U/L) 145 <200
Serum lactate dehydrogenase (U/L) 202 140-280

Mammography and ultrasound showed an irregularly shaped lump measuring 24 × 13 mm in the upper outer quadrant of the left breast and another lump measuring 12 × 10 mm at the junction of the upper quadrants of the same breast. The final Breast Imaging Reporting and Data System (BI-RADS) category was 5, strongly suggestive of malignancy (Figure 2). Contralateral breast results were normal. We also add that this was the first mammogram and first ultrasound ever performed on the patient.

The left mammogram revealed-an-irregular-shape-nodule-with-measurements-of-24×13mm-in-the-upper-outer-quadrant-of-the-left-breast-and-another-nodule - Measurement-12×10mm-at-junction-of-upper-quadrants-(yellow arrows).

A core biopsy was performed and the diagnosis was grade II invasive lobular carcinoma with positive progesterone and estrogen receptors (Fig 3). A thoracic, abdominal and pelvic CT scan was performed to determine metastatic processing of the tumor, which revealed a bilateral pleural effusion, two nodules with spiculed contours in the left breast, and multiple lesions in the skull and peripheral skeletal bones. Staging of the tumor was completed with a CT scan of the brain and cervix, which was free of abnormalities.

Histological section shows tumor proliferation arranged in discrete files (arrow), cords, discrete cells, and rare glands. The tumor cells were discohesive, small, monomorphic, and absent -marked-atypia.

The patient was then referred to another facility for further treatment.

Breast cancer is the second leading cause of death in women after lung cancer [5]since almost a quarter of breast cancers develop metastases during tumor progression and about 5% are metastatic at the time of initial cancer diagnosis [6]. Infiltrating lobular carcinoma (ILC), which accounts for 5% to 15% of all breast cancers, usually remains clinically silent and evades detection on mammography or physical examination until the disease is detected in advanced stages [7]. We report a case of lobular breast carcinoma with bilateral pleural effusion as the first sign.

Clinical breast examinations reveal vague findings such as thickening or induration. Clinical examination and early diagnosis of ILC are particularly challenging in patients with dense breast tissue or fibrocystic mastopathy. A high incidence of contralateral tumors in patients with ILC has been claimed [8]. In our case, the breast lesion was unilateral.

In metastatic disease, ILC has some distinctive patterns of metastatic spread compared to other histological breast cancers. More frequent spread to the peritoneum, gastrointestinal tract, bones and gynecological tract has been observed [9].

Pleural metastases are exceptional in ILC and occur at an advanced stage of the disease. It can rarely show a primary tumor. In a study by Cellerin et al. that focused on 209 malignant pleural effusions, ovarian and lung tumors (27%) were the most common primary site uncovered by pleural effusions in women, followed by mesothelioma (19.4%). [10]. Breast cancer was revealed by pleural effusion in only two patients. However, when the pleural effusion has metastasized to a known cancer, the primary site found in half of the cases (50%) was the chest, followed by lung cancer (14.5%) and lymphoma (10.5%). [10].

The study by Monte et al. of 126 malignant pleural effusions showed that the breast carcinoma did not initially appear with effusion in any case, although it was the most common malignant tumor in pleural effusions [11].

In a study of 105 breast cancer patients who had a pleural effusion as a direct result of metastatic disease, Fentiman et al. found that 48% of these tumors metastasized ipsilaterally, 42% contralaterally, and 10% of the tumors produced bilateral pleural effusions, as was the case in our patient [12].

Patients most commonly present with dyspnea, initially on exertion, a predominantly dry cough, and pleuritic chest pain [6]. In a study by Yahiaoui et al. in 158 patients, the diagnosis of malignant pleural effusion was confirmed by cytology in 71 cases (6%), by closed percutaneous needle biopsy in 55 cases (2%), and by thoracoscopy in 10 cases (4%) [13]. In a study of 170 malignant effusions, Aidou reported that needle biopsy was 75% contributory [14]. In our case, the diagnosis was made by blind pleural biopsy.

Patients with lobular carcinoma are treated with hormone therapy more often than patients with ductal carcinoma because of the higher frequency of hormone receptor-positive cells. Neoadjuvant chemotherapy is less recommended because of poor response unless the tumor is inoperable from the start [15].

For the treatment of a malignant pleural effusion, although chemotherapy or hormone therapy can achieve at least temporary resolution of the effusion in some cases, it will sooner or later recur. Among the available techniques, isolated pleural drainage is ineffective [16,17]. External radiation therapy is also ineffective on the pleura. Pleurectomy has a cost effectiveness of almost 100% but is associated with significant morbidity and mortality and is now abandoned for this indication [16]. Therefore, pleurodesis is the local treatment of choice for recurrent pleurisy requiring repeated evacuation [18].

For our patient, the decision was to start hormone therapy and chemotherapy; She also benefited from a bilateral thoracentesis without recurrence after four months of development.

The association between breast cancer and pleural effusion is common. However, in rare situations, a pleural effusion can reveal cancer, indicating an advanced stage of the disease. If indicated, the treatment of pleural effusion is essentially based on a pleurodesis, which enables a definitive pleural symphysis to be achieved and an improvement in the patient’s quality of life.